As methods of measuring a current position of a mobile station, there have been developed several methods. For example, a method of using GPS (Global Positioning System) has already been put into practice in a car navigation system or the like. Further, in a mobile communication system, there has been proposed a method of receiving radio wave transmitted from a base station by a mobile station and calculating a current position by using propagation time of the radio wave (refer to, for example, Japanese Patent Laid-Open (Kokai) No. Hei 7-181242).
As a service using the current position of the mobile station calculated by the above-described method, there is map display in navigation (refer to, for example, Japanese Patent Laid-Open (Kokai) No. Hei 1-173817). As approaching a destination, the scale of the map is changed and a route to the destination is selectively displayed.
Further, there also is Japanese Patent Laid-Open (Kokai) No. Hei 9-130859 in which although measurement of position is not carried out, in order to prevent ride past a station, entering a zone of a base station installed at the station is detected by checking a discrimination signature, whereby arrival at a destination is informed.